Due to their role as data storage and management devices, computers face threats from unauthorized access. Various software approaches have been implemented to provide protection. Passwords restrict access to only those users that have knowledge of the password. Firewalls are another software mechanism that protect computers from illegal access via a network.
These software approaches provide little or no protection from physical threats. That is, if someone tries to access the computer by operating the computer, the software can provide a moderately effective barrier. In contrast, if the unauthorized person seeks to access the computer's data by physically opening the computer and reconnecting the hard drive, for example, the software provides no safeguards.
Unfortunately, there is little or no way of cost-effectively hardening a computer against physical attack. In any organization, the computers are typically personal computers that are distributed throughout the organization's facilities, thus any person that has access to the organization's facilities generally may access the computers.
Some approaches have been proposed to detect the physical opening of the computer cabinet. Upon detecting this event, an attempt is made to disable the computer. In one case, the configuration RAM of the computer is cleared. The software or firmware of the computer is then designed to prevent the further operation of the computer in response to this clearance.